ISO 2007:2025

Rubber, unvulcanized - Determination of plasticity - Rapid-plastimeter method

This document specifies a method for the rapid determination of the plasticity of raw rubber and unvulcanized compounded rubber. It is applicable to the determination of the plasticity retention index (PRI) as specified in ISO 2930.

Caoutchouc non vulcanisé — Détermination de la plasticité — Méthode au plastomètre rapide

General Information

• Status: Published
• Publication Date: 15-May-2025
• ICS: 83.060 - Rubber
• Technical Committee: ISO/TC 45/SC 2 - Testing and analysis
• Drafting Committee: ISO/TC 45/SC 2/WG 2 - Visco-elastic properties
• Current Stage: 6060 - International Standard published
• Start Date: 16-May-2025
• Due Date: 05-Apr-2026
• Completion Date: 16-May-2025

Relations

• Revises: ISO 2007:2018 - Rubber, unvulcanized - Determination of plasticity - Rapid-plastimeter method
• Effective Date: 06-Jan-2024

Overview

ISO 2007:2025 - "Rubber, unvulcanized - Determination of plasticity - Rapid‑plastimeter method" specifies a standardized laboratory procedure for rapidly measuring the plasticity of raw rubber and unvulcanized compounded rubber. The method is suitable for determining the plasticity retention index (PRI) referenced in ISO 2930. This sixth edition updates apparatus requirements and adds precision data (Annex A) from an interlaboratory study.

Key topics and requirements

• Scope: Applies to raw natural and synthetic rubbers and unvulcanized compounds; intended for rapid plasticity measurement and PRI determination.
• Principle: A disc‑shaped test piece is preheated while compressed to 1.00 mm, then subjected to a constant compressive force (100 N ± 1 N) for 15 s; the final thickness is the plasticity measure.
• Apparatus: A parallel‑plate plastimeter with heated, parallel platens (selectable small platen diameters: 7.30 mm, 10.00 mm, or 14.00 mm), thickness indicator (0.01 mm resolution), force application and timing devices, punch for producing ~13 mm diameter discs, and specified tissue/cigarette paper.
• Test specimen: Disc ≈13 mm diameter, thickness 3.4 mm ± 0.2 mm; prepare and condition samples per ISO 1795 and ISO 23529. Prepare three test pieces; median of the three results (in hundredths of a millimetre) is the plasticity number.
• Test conditions: Standard test temperature 100 °C ± 1 °C; platen movement to 1.00 mm completed within 2 s; pre‑heating 15 s, test force period 15 s ± 0.2 s.
• Calibration & verification: Calibrate spring force and timing per ISO 18899; verify instrument using standard materials (e.g., standard butyl or NIST reference NBS‑388).
• Precision: Annex A reports interlaboratory repeatability and reproducibility (example ranges: r ≈ 0.2–0.7 units, R ≈ 2.4–3.1 units; relative reproducibility ≈ 7.5–9.7% for tested materials).
• Test report: Must include sample ID and preparation, reference to ISO 2007:2025, platen size, test temperature, plasticity number, and date.

Applications and users

• Who uses it: Rubber testing laboratories, quality control (QC) teams in rubber manufacturing, compounders, material development laboratories, and third‑party testing/inspection bodies.
• Practical uses:
  • Rapid QC acceptance testing for raw rubber and unvulcanized compounds.
  • Measuring baseline plasticity and assessing plasticity retention index (PRI) for aging/stability studies.
  • Supporting formulation control and batch consistency in tire, hose, seal and other rubber product manufacturing.
  • Instrument verification and interlaboratory comparisons.

Related standards

• ISO 2930 - Plasticity retention index (PRI) procedures (method linkage)
• ISO 1795 - Sampling and preparative procedures for raw rubber
• ISO 23529 - Preparing and conditioning test pieces
• ISO 18899 - Guide to calibration of test equipment

Keywords: ISO 2007:2025, rapid‑plastimeter, rubber plasticity, plasticity number, PRI, unvulcanized rubber, plastimeter test method, rubber testing, QC.

Standards Content (Sample)

International
Standard
ISO 2007
Sixth edition
Rubber, unvulcanized —
2025-05
Determination of plasticity —
Rapid-plastimeter method
Caoutchouc non vulcanisé — Détermination de la plasticité —
Méthode au plastomètre rapide
Reference number
© ISO 2025
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
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CH-1214 Vernier, Geneva
Phone: [phone]
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Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus . 2
6 Test piece . 5
7 Calibration . 5
8 Temperature of test . 5
9 Procedure . 5
10 Expression of results . 5
11 Precision . 6
12 Test report . 6
Annex A (informative) Precision . 7
Bibliography . 9

iii
Foreword
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This document was prepared by Technical Committee ISO/TC 45, Rubber and rubber products, Subcommittee
SC 2, Testing and analysis.
This sixth edition cancels and replaces the fifth edition (ISO 2007:2018), which has been technically revised.
The main changes are as follows:
— revision of subclause 5.3;
— addition of Annex A.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
International Standard ISO 2007:2025(en)
Rubber, unvulcanized — Determination of plasticity — Rapid-
plastimeter method
WARNING — Persons using this document should be familiar with normal laboratory practice. This
document does not purport to address all of the safety problems, if any, associated with its use. It is
the responsibility of the user to establish appropriate safety and health practices and to determine
the applicability of any regulatory conditions before use.
1 Scope
This document specifies a method for the rapid determination of the plasticity of raw rubber and
unvulcanized compounded rubber. It is applicable to the determination of the plasticity retention index
(PRI) as specified in ISO 2930.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 1795, Rubber, raw natural and raw synthetic — Sampling and further preparative procedures
ISO 18899, Rubber — Guide to the calibration of test equipment
ISO 23529, Rubber — General procedures for preparing and conditioning test pieces for physical test methods
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
plasticity number
measure of plasticity, based upon the height of a test piece after being subjected to deformation under
specified conditions of compressive force, time and temperature
[SOURCE: ISO 1382:2020, 3.359]
4 Principle
A disc-shaped test piece is compressed rapidly between small parallel platens to a fixed thickness of 1 mm.
The test piece is maintained at this compression for 15 s to enable it to reach approximate temperature
equilibrium with the platens. After this period, the test piece is subjected to a constant compressive force of
100 N ± 1 N for 15 s. Its thickness at the end of this period is taken as the measure of plasticity.

5 Apparatus
5.1 Parallel-plate plastimeter, consisting of the following elements:
5.1.1 Two parallel, circular platens, having smooth, flat surfaces, movable in relation to each other,
both provided with suitable means of heating, and a jacket so that the material being tested and the area
surrounding it can be maintained at the specified test temperature.
One of the two platens shall be a right cylinder of stainless steel and shall have one of the following diameters:
a) 7,30 mm (tolerance ±0,02 mm);
b) 10,00 mm (tolerance ±0,02 mm);
c) 14,00 mm (tolerance ±0,02 mm).
The effective depth of the platen shall be 4,50 mm ± 0,15 mm. Care shall be taken to ensure that the edge of
the working face is neither worn nor damaged. The diameter shall be selected so that the measured plasticity
(see Clause 10) lies between 20 and 85. The other platen can be of chromium-plated brass or stainless steel
and shall be of a larger diameter than the first pl
...